FIELD: biotechnology.
SUBSTANCE: fusion polypeptide for preparation of a soluble Fc receptor of the formula R1-FC-R2 (Formula I) wherein R1 is the first Fc receptor, R2 is the second Fc receptor, and FC is the heavy chain Fc region polypeptide containing R1 or R2, or both, wherein FC does not substantially bind to R1 and/or R2, wherein R1 and R2 are independently selected from the group of the human gamma Fc receptor, the human neonatal Fc receptor, the murine Fc receptor and the rabbit neonatal Fc receptor, and where FC is a human IgG1 heavy chain polypeptide, which has L234A, L235A and P329G mutations. A fused polypeptide is also described for preparation of a soluble Fc receptor with formula II (see claim 2), wherein R1 is the first Fc receptor, R2 is the second Fc receptor, FC is the heavy chain Fc region polypeptide, CS1 is the first cleavage site, CS2 is the second cleavage site, CS3 is the third cleavage site, CS4 is the fourth cleavage site, L1 is the first linker, and L2 is the second linker containing R1 or R2, or both, wherein any of CS1, CS2, CS3, CS4 may or may not be present, regardless of others, wherein L1 and L2 may or may not be present independently, or wherein FC does not substantially bind to R1 and/or R2, wherein R1 and R2 are independently selected from the group of human Fc gamma receptor, human neonatal Fc receptor, murine Fc receptor and rabbit neonatal Fc receptor, and wherein FC is a human IgG1 heavy chain polypeptide which has L234A, L235A and P329G mutations. A dimeric fusion polypeptide is also provided to produce a soluble Fc receptor containing any two described fusion polypeptides. Application of the immobilized described fusion polypeptide as an affinity chromatography ligand is presented. Application of an immobilized fusion polypeptide according to any one of claims 1-8 to determine antibody binding to the Fc receptor is presented.
EFFECT: invention allows to obtain soluble Fc receptors by carrying out Fc receptor expression as a fusion polypeptide.
12 cl, 7 dwg, 1 tbl, 10 ex
